If a motor vehicle has a so-called "active" antenna, i.e. an amplifier-equipped antenna, this must be supplied with operating voltage. This operating voltage is conventionally supplied through a cable connected to an operating voltage terminal.
It is known, in stationary installations like household antennas, to use the antenna cable to supply operating voltage to an antenna amplifier, with coupling-in and coupling-out carried out using filters provided for this purpose. However, due to the substantial noise pulses which are common at the operating voltage terminals in motor vehicles, it has heretofore been necessary to refrain from double use of the antenna cable, and to supply operating voltage to the antenna amplifier by a separate cable.